Method and apparatus for producing staple fiber yarn



May 27, 1952 .H. VON KOHORN 2,598,086

METHOD AND APPARATUS FOR PRODUCING STAPLE FIBER YARN- Filed Oct. 5, 1946 2 SHEETS-SHEET 1 INVENTOR. HENRY vo/v KOHORN BY '2 {z fi 7' TORNE YS y 27, 1952 H. VON KOHORN 2,598,086

METHOD AND APPARATUS FOR PRQDUCING STAPLE FIBER YARN Filed Oct. 5, 1946 2 SHEETS-SHEET 2 Tm "EL-1mm INVENTOR; HENRY VON KOHOPN BY H HTTORNEYS Patented May 27, 1952 UNITED STATES METHOD AND APPARATUS FOR PRODUCING STAPLE FIBER YARN 7 Claims. 1

The present invention relates to an improved method and apparatus for the production of staple fiber yarn and it relates more particularly to an improved method and apparatus for the production of staple fiber yarn from bundles of continuous filaments.

In the manufacture of staple fiber yarn by methods now generally employed, the staple fiber assumes a random mixed condition at some stage in the production. Where the staple fiber is produced by the viscose method, a tow of freshly spun continuous filaments is cut into staple fibers and the staple fibers are subjected to the usual liquid aftertreatment and drying stages or the tow is subjected as such to liquid aftertreatment and then cut into staple fibers, opened and dried. In either case, the staple fibers are formed in a tangled mixed condition and must be subjected to the numerous steps employed in the production of cotton yarn such as carding, combing, drawing, spinning, etc.

Inasmuch as the filaments from which the staple fibers are formed are originally in a parallel condition, it is highly inefficient to destroy this condition and thereafter have to subject the tangled staple fibers to combing and carding operations. Such action necessarily entails additional expensive machinery, increased production time and an overall increase in cost.

There have been numerous methods proposed for producing a staple fiber yarn from a bundle of continuous filaments without disturbing the original condition of parallelism of the fibers, but these methods have their shortcomings and result in yarns of inferior quality. One of the proposed methods consists in passing a bundle of continuous filaments between two sets of rotating rollers, the withdrawing set of rollers running at a greater peripheral speed than the feeding set. The filaments are thus stretched and torn into staple fibers of different lengths, the ends of the fibers being staggered so that a sliver of staple fibers is formed. This sliver may, then be drafted and twisted in any suitable manner to form a yarn of staple fiber. The above method possesses many undesirable features. Among these are the non-uniformity in the lengths of. the staple fibers and the reduced elasticity of the finished yarn as a consequence of the stretching of the fibers.

Another method which has been proposed consists in passing a twisted bundle of continuous filaments over a multiple bladed cutting roller which runs at a different peripheral speed than the speed of the moving bundle. The bundle of ATENT OFFICE filaments is lightly pressed against the cutting roller so that only a very few filaments are cut by each blade upon contact with the bundle. Since the blades are closely spaced so that the cutting frequency is high and the bundle is twisted, a yarn containing staple fibers of a short average length may be obtained. However, it is apparent that the staple fibers are entirely of non-uniform length. Some filaments will not be cut at all. Moreover,-this method requires as a starting material a twisted bundle of continuous filaments so that before the filaments are out they must be suitably twisted and wound upon cops or spools, thereby interrupting the continuity of the process.

It has also been proposed to pass a bundle of continuous filaments diagonally over the surface of a rotatable abrasive wheel, thereby driving the wheel and severing the filaments along their lengths. The bundle of severed filaments is then twisted to produce a yarn. In addition to other shortcomings, the staple fibers formed by this method are of random lengths.

According to still another method, a bundle of continuous filaments is transported between two pairs of rollers and a reciprocating comb-shaped blade, upon each stroke, cuts a small part of the filaments and is periodically shifted transversely to sever another part of the filaments upon the following stroke. The bundle is then passed through a pair of rollers having a greater peripheral speed than the preceding rollers, thereby to tear the filaments which have not been severed by the reciprocating comb-shaped blade.

In addition to those described above, numerous other methods have been proposed for producing a staple fiber yarn directly from a bundle of continuous filaments Without materially disturbing the condition of parallelism of the filaments. However, none of these methods have proven very successful, either in the final product achieved or in the operation of the apparatus employed.

It is therefore an object of the present invention to provide an improved method and apparatus for producing a yarn of staple fiber from a bundle of continuous filaments.

Another object of the present invention is to provide an improved method and apparatus for producing a yarn of staple fiber from a bundle of substantially parallel continuous filaments without disturbing the parallel condition of the filaments.

Still another object of the present invention is to provide an improved simple method and apparatus for continuously producing from a bundle 3 of substantially parallel continuous filaments a staple fiber yarn wherein a major portion of the staple fibers are of uniform length.

A further object of the present invention is to provide an improved mechanism for cutting continuous filaments into staple fibers.

Still a further object of the present invention is to provide an improved method for stabilizing a thread of continuous filaments.

Another object of the present invention is to provide an improved staple fiber yarn.

The above and further objects of the present invention will become apparent upon a reading of the following description taken with the accompanying drawings wherein Fig. 1 is a front elevational view of an apparatus embodying the present invention; Fig. 2 is a partial side elevational view thereof; Fig. 3 is a front elevational view of another embodiment of the present invention; Fig. 4 is a front elevational view of still another embodiment of the present invention; Fig. 5 is a plan view ther of; Fig. 6 is a' detailed view turned 90 counterclockwise of a portion thereof; and Fig. 7 is a plan view of an improved cutting device which may be employed in the present apparatus. The present invention broadly contemplates feeding a bundle of continuous filaments to a cutting device to effect the severing at predetermined points and into uniform lengths of only a portion of the continuous filaments. The bundle isthen subjected to a drafting operation whereby the remaining uncut filaments are torn and the resulting sliver may be immediately twisted and wound or may be subjected to additional drafting stages before the final twisting and formation of a yarn. The severing of the continuous filaments at predetermined points and into uniform lengths may be accomplished either prior to the drafting and tearing operation or simultaneously therewith. Further, although the original bundle of continuous filaments may be a high denier tow, which necessitates numerous drawing stages before production of the final yarn, it is preferred that the original bundle be ofa thickness of the order of about 5,000 denier so that a single cutting and drafting operation is the only step required before the twisting and winding of the final yarn.

Reference is now made to the drawing and more particularly to Figs. 1 and 2 thereof, wherein there is illustrated an apparatus for converting a small denier bundle of continuous filaments into a spun rayon yarn wherein only a single drafting and cutting operation is employed. The apparatus includes afirst, or upper, pair of positively driven drawing rollers H and i2, and a second, or lower, pair of positively driven drawing rollers l3 and It. the first and second pairs of rollers being driven at different peripheral speeds as will be hereinafter set'forth.

The upper roller i2 is provided with a helical knife l6 disposed about the surface of the roller l2. The knife I6 is provided with a series of gaps H, the gaps H afiording uninterrupted circumferential passages along the surface of the roller I2. The longitudinal extent of the gaps may be about 5% of the longitudinal extent of the knife I61 Further, the roller H has formed thereiri'a helical groove, indicated by dotted lines in Fig. L'Which groove registers with a knife |5 so that the surfaces of the rollers I and 52 are normally in contact with each other.

At least one of the upper rollers H and 2 is mounted on a shaft 20, which shaft is in turn coupled to a gear 2|. Similarly, one of the lower rollers I3 or I4 is mounted on a shaft 22, which, in turn, is coupled to a gear 23, said gear 23 being of smaller circumference than gear 2|. Further, a drive gear 24, engaging the gears 23 and 2|, is positively driven by way of a drive shaft 26 so that at least one roller of each pair of rollers is positively driven, that of the upper set of rollers being driven at a lower circumferential speed than that of the lower set of rollers. Directly below the rollers l3 nad l lis a winding and twisting mechanism which may take any well-known form and generally includes a thread guide 21, a traversing guide 28 and a rotating spindle 29.

Considering now the operation of the appa ratus illustrated in Figs. 1 and 2, a bundle 3|] of continuous filaments which has been previously flattened by any well-known means to assume a ribbon-like configuration is fed to the upper pair of drawing rollers It and l2. The bundle 30 is preferably of a low denier, for example of approximately 3,000 to 5,000 denier. The bundle 30 is drawn by the roller-s and l2, and a major part thereof is cut by the knife l6 into staple fibers of uniform length, the ends of the fibers being regularly staggered. The staple fibers maintain their original parallelism as a result of being intermingled with the continuous filaments which have passed through the gaps I? of the knife I6 and have thus remained uncut.

The bundle 30 is then fed between the lower rollers I3 and M, which rollers are driven at a circumferential speed determined by the desired thickness of the final yarn. It is obvious that the continuous filaments which have passed through the rollers H and I2 are torn between the two sets of rollers as a result of the stretch effected between said rollers, and that a thin sliver 33 emerges from the rollers l3 and is and is composed entirely of staple fibers, the major portion of which have been cut into uniform lengths and the remainder of which have been torn into staple fibers having a random staggered relationship in the sliver 33. The lengths of the torn filaments are determined by the distance between the two pairs of drawing rollers, the relative speed of the rollers and the elongation of the filaments. These variables may be so correlated that any desirable length may be obtained, preferable lengths being from one to six inches. The sliver is then guided through the guide 21 and through the traversing ring guide 28 where it is suitably twisted and wound upon cops or cones. It should be noted that a larger starting bundle 3|} may be employed, for example between 5,000 and 50,000 denier, and the drawing stage or stages accordingly modified to obtain the desired final product.

In Fig. 3 of the drawing, there is illustrated an arrangement for cutting and drawing a bundle of continuous filaments into a sliver of staple fibers, differing from the above described embodiment only in that the cutting operation is performed by a separate set of cutting rollers.

Specifically, a first, or upper, pair of rollers 40 and 4|, and an intermediate pair of drawing rollers 62 and 43 are positively driven at substantially the same peripheral speed. The upper roller 4| is provided with a helical knife 44 interrupted by the gaps 46, the helical knife 44 being disposed along the surface of the roller 4|. The roller 4|! is urged into the contact with they knife 44. A lower set of drawing rollers 41 and 48 disposed immediately below the drawing rollers 42 and 43 are positively driven at a greater peripheral speed than the rollers 42 and 4 3, In operaparallelism as a result of the intermingled continuous filaments, and as such, is fed to the two sets of drafting rollers 42, 83 and 41, 48. The continuous filaments are then torn between the two sets of drawing rollers, and the resulting sliver of staple fibers as emerging from the rollers 41 and 88 may be suitably twisted and wound as above described.

Referring-now to Figs. 4 to 6 in the drawing, there is illustrated still another embodiment of the presentinvention wherein the cutting operation is effected between two pairs of differentially driven drawing rollers. More particularly a first pair of drawing rollers 58 and 5| precedes a second pair of drawing rollers 52 and 58, the first pair of drawing rollers being driven at a lower peripheral speed than the second pair of drawing rollers. A continuous belt 54 driven by the roller 5| extends from the first pair of rollers 58, 5|, to the second pair of rollers 52, 53, and is guided by way of idlers 58. A pair of cooperating cutting rollers 57 and 59 is disposed above and below the belt 54 and is in alignment with the first and second pairs of drawing rollers. The cutting rollers 51 and 58 are each provided with the series of knives or other cutting elements 59, which knives 59 are circumferentially and longitudinally staggered along the surfaces of the cutting rollers 5'1 and 58 and are alternately arranged on each of the cutting rollers so that a series of staggered and regularly spaced cuts are effected by the knives 59 on the rollers 51 and 58. Further, the circumferential extensions of the individual knives 59 are spaced so that the aggregate cut of the knives 59 does not extend uninterruptedly across the belt 58. The belt 58 is provided with the slits 55 which register with the knives 59 on the rollers 51 and 58. It should be noted that the rollers 51 and 58 are driven at a circumferential speed substantially equal to the speed of the rollers 58 and 5| The drawing rollers 5| and 53, and the cutting roller 5'! may be driven by respective drive belts 15, El, and 18 which are in turn connected to a suitable power source or sources.

An arrangement shown in Fig. 6 is provided for urging at an adjustable pressure the rollers 51 and 58 toward each other. A pair of arms 88 and 8| are pivotly connected by an axle 58 upon which is rotatably, mounted a gear 85. The free ends of the arms 88 and 5| are supported on shafts 85 and 88, upon which are mounted the rollers 51 and 58 and gears 87 and 88 shaft85 being supported in relatively fixed position by any well-known structure, not illustrated. A shaft bearing 78 is fixed to the lower end of a bolt H, the upper end of the bolt extending through a compression spring 12 and through an aperture in the member 13 which is supported in a fixed position relative to the shaft 85 by any suitable means, not illustrated. The free end of the bolt II is engaged by a wing nut 14 so that the pres sure between the cutting rollers 51 and 58 may be controlled by adjusting the wing nut 14. While the cutting roller 5! is illustrated as being adjust- 6 ably urged toward the relatively fixed cutting roller 58, it is apparent that either roller 5'1 or 58 may be suitably urged toward the other or toward each other so long as the belt 54 passes between the rollers 5! and 58 as illustrated in the drawing.

In operation, a bundle of continuous filaments 38 is fed between the rollers 58 and 5| and is conveyed by the belt 54 to the rollers 51 and 58, where a series of staggered cuts are imparted to the bundle 88. It should be noted that inasmuch as the knives 59 do not extend continuously across the width of the bundle 38, some of the filaments forming the bundle 38 remain uncut and therefore continuous. The partially cut bundle 32 is then subjected to the drafting operation between the two pairs of drawing rollers so that the remaining continuous filaments are torn and the sliver emerging from the rollers 52 and 53 is formed completely of staple fibers and is of a thickness in relationship to the bundle 30, in accordance with the ratio of the peripheral speeds of the rollers 52, 53 and 58, 5|. The sliver 33 of staple fibers may then be subjected to further drawing operations, or if the starting bundle 38 was suficiently small, the sliver 33 may be directly twisted and wound.

A pair of cutting or severing rollers which may be advantageously employed in the present device is illustrated in Fig. 7 of the drawings. A pair of positively driven rollers 88 and 8| are urged toward each other by any well-known arrangement. The roller 88 is provided with a series of abrasive elements 82 projecting from the surface of the roller 88, the abrasive elements 82 being helically arranged along the surface of the roller 88 and being longitudinally spaced so as to provide a free passage for the fraction of the filaments subjected to the cutting action of the rollers and 8|. Further, the roller 8| is provided with a substantially rigid tapered core 83 and a resilient sheath 84, the outer surface of the sheath being cylindrical and the inner surface conforming to the surface of the core 83.- Upon the rollers 80 and 8| being rotated and one of the elements 82 coming into contact with the confronting surface of the resilient sheath 84, the filaments engaged between the cutting element 82 and the sheath 84 are urged laterally across the abrasive element 82, thereby severing the filament by abrasion against the element 82. The lateral movement of the filament against the abrasive element 82 is caused by the axial movement imparted to the sheath 84 as a result of the inclined surface 86 of the core 83 and the radial compression imparted to the sheath 84 by the contacting abrasive element 82. It should be noted that the sheath 88 may be formed of rubber or any other suitable material, and the abrasive elements 82 may be formed of carborundum, roughened metal, or the like.

While I have described preferred improvements of the present invention, it is obvious that numerous alterations and omissions may be made without departing from the spirit thereof.

I claim:

1. Apparatus for the production of staple fiber yarn from a bundle of continuous filaments comprising a pair of feed rollers, a pair of drawing rollers, means for driving at least one of said feed rollers, means for driving at least one of said drawing rollers at a greater peripheral speed than said feed rollers, a pair of cooperating filament cutting rollers disposed between said draw: ing and feeding rollers, said filament cutting 7 drawing rollers at a greater peripheral speed than said feed rollers, a pair of cooperating filament severing rollers disposed between said drawing and feeding rollers, said filament severing rollers being provided with means for severing only a portion of said bundle of continuous filaments into staple fibers of predetermined uniform length in staggered, side-by-side relationship the re.- maining portion of said bundle of continuous filaments being torn between said feeding and drawing rollers.

3. Apparatus for producing spun rayon yarn from a bundle of continuous filaments, comprising a drafting mechanism, including two pairs of rollers driven at different peripheral speeds, a third pair of cooperating filament severing rollers disposed between said two pairs of rollers, means for driving at least one of said severing rollers, and a plurality of cutting devices circumferentially disposed on one of said severing rollers,

each. of said devices extending longitudinally along said roller.

4. Apparatus for producing spun rayon yarn from a bundle of continuous filaments, comprising drafting mechanism, including two pairs of rollers driven at different peripheral speeds, a third pair of cooperating filament severing rollers disposed between said two pairs of rollers, means for driving at least one of said severing rollers, and a plurality of knives disposed on one of said rollers and arranged in staggered relation along the surface thereof.

5. Apparatus for producing spun rayon yarn from a bundle of continuous filaments, compris ing a drafting mechanism including two pairs of rollers driven at different peripheral speeds, a third pair of cooperating filament severing rollers disposed between said two pairs of rollers, means for driving at least one of said severing rollers, and a plurality of knives disposed on one of said severing rollers and arranged in staggered relation along the surface thereof, the longitudinal extent of all of said knives being less than the length of said roller.

6; Apparatus for producing spun rayon yarn from a bundle of continuous filaments comprising drafting mechanism, including two pairs of rollers driven at different peripheral speeds, a driven conveyor belt extending between said pairs of rollers, a severing roller disposed between said pairs of drafting rollers and a plurality of cutting devices circumferentially disposed on said severing roller, each of said devices extendin longitudinally along said severing roller.

7. In the production of spun rayon yarn, the steps comprising subjecting a bundle of continuous filaments to a draft, sufficient to rupture said filaments, and cutting a portion of said bundle of continuous filaments while subjected to said draft while leaving predetermined portions of said bundle of filaments uncut.

HENRY VON KOHORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,003,400 Taylor June 4, 1935 2,077,320 Hale Apr. 13, 1937 2,142,475 Lohmann Jan. 3, 1939 2,221,022 Ellis Nov. 12, 1940 2,234,105 Ashton Mar. 4, 1941 2,294,771 Campbell Sept. 1, 1942 2,323,300 Abbott July 6, 1943 2,419,320 Lohrke Apr. 22, 1947 2,427,955 Furness Sept. 23, 1947 

